The present invention relates to a design of a table which serves multiple purposes as a coffee table and/or dinner table. For this purpose the table is vertically adjustable from a low coffee table height, such as 18 inches, continuously up to a dining table height, such as 29 inches. Other height ranges can also be encompassed, such as a table height for standing use.
In the majority of motor homes and other recreational vehicles currently produced the design focus is on providing a social gathering area which must double as a dining area because of limited space. This gives rise to the need for a table which can serve the dual purpose of a coffee table and a dining table. The present invention addresses this need by providing a table that can be easily raised from coffee table height to dining table height.
Other areas where this present invention is useful are in efficiency and studio apartments and in boats where space is also at a premium. Still other potential areas of use are in child care and elder care where a table easily adjustable can satisfy the need for a specific height.
Prior art includes several designs intended to fill this need. Although these designs currently on the market can fill the basic requirement of coffee table height and dining table height, they are universally difficult to change from one height to another and are generally limited to two specific predetermined heights. They continue to generate dissatisfaction among those who use them. Most require skill and/or physical strength to change the subject table from one height to another height.
The following patents have some relevance to adjustable-height tables or other adjustable-height devices: U.S. Pat. Nos. 7,246,779, 7,182,323, 6,997,116, 6,874,432, 6,840,582, 6,578,501, 6,571,720, 6,536,357, 6,435,110, 6,378,671, 6,343,556, 6,283,047, 6,227,357, 6,101,956, 5,553,550, 5,513,825, 5,438,939, 5,322,025, 5,313,892, 5,197,393, 4,436,007, 3,710,735 and 3,080,835. Of these patents, U.S. Pat. No. 6,283,047 discloses an adjustable-height table that can work on a pneumatic principle, i.e. an air spring. In the principal embodiment a double pivot is involved, with the table top swung upward or downward on an arm, thus displacing the horizontal position of the table as it is raised or lowered. In a second embodiment the movement of the table top is vertical, with a “bellows cylinder” or bellows type spring acting against gravity exerted on the table top and associated frame. A reservoir separate from the bellows cylinder is included. That table did not provide for a guiding assembly to provide stability of the table against lateral, tipping or rotating motion, through all the range of height adjustment, as in the present invention described below. Moreover, that patent involved a separate and spaced apart air reservoir connected by a fluid line to the pneumatic cylinder or bellows cylinder that exerted upward force on the table top.
U.S. Pat. No. 7,182,323 also employs a type of pneumatic spring, but in a much different arrangement from that of the present invention. Several of the other patents in the above list employ mechanical lifting devices, motorized or hand-rotated. Some use hydraulic cylinders, not necessarily for table tops as in the current invention.